Question

A box contains 3 black balls, 4 red balls and 3 green balls. All the balls are identical in shape and size. Rohit takes out a ball from the bag without looking into it. What is the probability that the ball drawn is a black ball?

• A. $\frac{3}{10}$
• B. $\frac{4}{10}$
• C. $\frac{2}{5}$
• D. $\frac{1}{2}$

Answer 1

The correct option is A

$\frac{3}{10}$

Given,

Number of black balls in the bag = 3

Number of red balls in the bag = 4

Number of green balls in the bag = 3

Total number of balls in the bag = 3 + 4 + 3 = 10

Number of favourable outcomes = 3

Probability of drawing a black ball, P(black ball)=$\frac{\text{number of favourable outcomes}}{\text{total number of outcomes}}$

$\Rightarrow \text{P(black ball )}=\frac{3}{10}$